Due to the increasing energy demands, offshore oil and gas production is moving into deeper waters. For ensuring an efficient and secure production from a subsea well, processing facilities are being installed at the ocean floor. Such subsea installations can comprise a range of components, including pumps, compressors, and the like as well as a power grid for providing such components with electric power. Such power grid may for example comprise a subsea transformer, subsea switchgear and subsea variable speed drives. The components of the subsea installation need to be protected from the surrounding seawater, in which pressures of up to 300 bar or more can prevail, e.g. at installation depths of 3.000 m or more.
Other components that may need to be supplied with electric power include control components, such as subsea control units, communication equipment, sensors and the like. In conventional power distribution systems, a fault in the system generally causes a blackout of the complete system. Accordingly, the subsea installation is no longer operable and production must be stopped. This may lead to significant financial losses for the operator of the subsea well.
Accordingly, it is desirable to supply electric power to the components of a subsea installation with high reliability. In particular, a complete blackout of the subsea power grid should be prevented. Furthermore, it is also desirable to allow the servicing of individual components of such subsea installation without the need to completely shut down the subsea power grid.